The imperial system is a system of weights and measures that was originally developed in England. It uses length units: inch, foot (12 inches), yard (36 inches), mile (5,280 feet). It uses weight units: ounce, pound (16 ounces), ton (2,000 pounds). It uses volume units: quart, gallon (4 quarts). In most countries, the metric system has replaced the imperial system since it is more logical and consistent mathematically.